Hmmm...not sure of anything like that. I would bet you could just tell them to not clean the windows and eventually they'd just get dirty enough.
Seriously, though, if it's intended to let people know when somebody is smoking in that room, I think I could suggest an option, though it will likely be very expensive.
There is a type of glass called Electrochromatic Glass, or similarly, SPD Glass, that can turn from clear to opaque, or colored, when a current is passed through the glass. I would venture to guess that a system could be designed whereby a smoke detector could detect a person smoking, and rather than setting off an alarm, could signal other equipment to send a current through the glass, thereby turning it opaque until such time that it was reset.
Just my thoughts, not really knowing the intent of the idea.